Using USB without Visa

[eagerstudent]

"I have a usb camera that has it's own drivers. I want to stream the video to the user via the front panel. I don't know the exact functions declaration that are in the dll to use with Code library function. I thought about using vfw but could not figure out exactly how to do that. I want to stay away from IVision or WebCam Library. Is there a way to figure this out? Thanks for tips and ideas."

[Robert M]

Hello eagerstudent,

You basically have two options.

You can call the dlls in LabVIEW using a �Call Library Function Node� as you have mentioned. You will have to figure out what methods to call, what they return, and how to cast that data into images. This is probably the more difficult method.

Your other option, if it is available, is to use ActiveX to control whatever application you use to view your camera video and pull that streaming into LabVIEW. What functionality is available will be up to whatever application you control, but most robust applications provide at the very least a basic, usable interface. The ActiveX controls for the application will be registered with your OS when the application is installed. You can then use an Active
X container in LabVIEW to reference the ActiveX object. I�ve attached an example that does exactly this with Windows Media Player.

If none of these suggestions help, or if I�m not correctly understanding your issue, please reply with comments or answers to the discussion above and any additional information that may help, and I�ll be happy to look further into it.

Have a nice day!

Robert Mortensen
Applications Engineer
National Instruments

[eagerstudent]

Hi Robert,
Thanks for the feedback. The software that came with the camera does not have activex. I got over the problem by using the lv_vfw example and caputring a image and refreshing the image. This makes it like a streaming video but the problem is the picture flickers as it's updating everytime in the loop.
Thanks again.

[Poormanphysics]

Hello:

I recently followed this thread now it seemed I have a similar problem. May I obtain from you the example program you used? (LV_LFW?). My application is on remote microscopy.

Thanks,

Berns B.

[AESulzer]

Berns,

I can't speak entirely as to exactly which files eagerstudent was referencing but here is a link that gives the location of some VIs of the same name (lv_vfw). They seem pretty old, so I hope they work for you!

Kind Regards,